Fitted sheets are typically configured to cover a substantial portion of a mattress and engage the mattress to obviate undesired movement of the fitted sheet. Typically, fitted sheets are provided with at top panel, side panels extending from the edges of the top panel and elastic along all of the exposed edges of the side panels or along the exposed edges of two opposite side panels. The side panels are sized so that a portion of the side panels can be tucked underneath the mattress and held in place by the elastic.
Mattresses are sold in several sizes. The most common sizes are twin, twin XL, double (also called full size), queen, king and California king. Most fitted sheets available in the market are made to fit one size mattress. U.S. Pat. No. 9,820,592 B2 discloses a fitted sheet that is made to fit both a twin mattress and a twin XL mattress. This fitted sheet as elastic strips in the corners which stretch in only one direction.
The art has recognized that one can make the corners of a fitted sheet to contain elastic threads so that the sheet will fit more securely on a mattress. U.S. Pat. No. 2,624,893 discloses a sheet for a crib in which elastic threads are provided. These threads run in a single direction from the exposed edge of the sheet toward the top panel. U.S. Pat. No. 4,980,941 discloses a fitted bedding product in which portions of the side panels are made of an elastic material.
When fitted sheets fit only one size of a mattress retailers and wholesalers must stock a sufficiently large inventory to have a fitted sheet in at least the most popular colors that fits each of the commonly available mattresses. It also forces purchasers to buy specifically-sized fitted sheets for each size of mattress in their household or establishment. Wooten recognized this problem and attempted to solve the problem by providing a fitted sheet disclosed in his U.S. Pat. No. 6,983,500 B2. That product includes a top portion, opposite side portions, opposite end portions, and elastic segments connected between adjacent edges of respective side and end portions. Wooten teaches that each of the segments is a flat piece of material having an attached edge that may have an ellipse shape, a circular shape or a crescent shape and a free straight edge. FIGS. 1 and 2 of the patent show one embodiment that is fitted snugly on a full size mattress and FIGS. 3 and 4 show the same fitted sheet snugly fitted on a queen size mattress. However, we made a fitted sheet as taught by the '500 patent which fit snugly on a queen mattress as shown in FIGS. 3 and 4 of the patent. However, when we put the same sheet on a full size mattress the corners and the side panels were loose and wrinkled.
We also made a sheet in accordance with the teaching of U.S. Pat. No. 4,980,941 that snugly fit a queen mattress and another sheet according to the teaching of U.S. Pat. No. 2,624,893 that snugly fit a queen mattress. When we put each of these sheets on a full size mattress, both of them did not fit the full size mattress. The corners and the side panels were loose and wrinkled.
There is still a need for a fitted sheet that will fit on each of two mattresses that are different in size, such as a full and a queen, or a king and a California king. A need also exists for fitted sheets that, when mounted on a mattress, will have no seam ears or pockets at their corners.